Amide ion (NH₂⁻)

The amide ion is a nitrogen atom bonded to two hydrogen atoms, carrying a 1− charge. It forms when ammonia, NH₃, loses a hydrogen ion, H⁺, but keeps the bonding electrons, so it has one more electron than it has protons. It is such a strong base that it reacts at once with water, so chemists use it only under dry conditions, often dissolved in liquid ammonia.

• Ammonia sits in the middle of a series: add H⁺ to get ammonium, NH₄⁺, or remove H⁺ to get amide, NH₂⁻.
• In organic chemistry, amide also names neutral molecules that contain a C(=O)N group, such as the links between amino acids in proteins, so check which meaning is intended.
• Sodium amide, NaNH₂, is used to make indigo dye and other chemicals that need a very strong base.

Compounds that contain amide

Other ions with a −1 charge